Understanding Storm Track Position and Intensity Across a Range of Timescales

了解不同时间尺度内的风暴轨迹位置和强度

• 批准号: 1742944
• 负责人: Tiffany Shaw
• 金额: $ 45.04万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-02-01 至 2022-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1742944&HistoricalAwards=false
• 关键词: Understanding; Storm; Track; Position; Intensity

Warm days preceding and cold days following the passage of frontal weather systems are a familiar feature of winter weather in the continental US and other middle latitude regions. This alternation is important not only for local weather but for the global transport of heat and moisture, as warm moist air crosses the middle latitudes from the tropics to the poles while colder and drier transits in the opposite direction. This north-south exchange of heat and moisture plays an essential role in earth's climate, keeping the poles from getting too cold while limiting the temperature excess of the tropics. Such climatic effects of weather systems are commonly studied by looking at the midlatitude stormtracks, defined as zones of maximum weather system activity. In the Northern Hemisphere separate stormtracks are centered over the northern North Pacific and North Atlantic, while in the Southern Hemisphere a continuous stormtrack extends around the "roaring 40s" over the uninterrupted Southern Ocean.This project seeks to understand how the mean latitude of the stormtracks, and the and strength of the energy transport by the weather systems moving along them, change in response to external factors including the seasonal cycle of solar heating, greenhouse gas concentrations, stratospheric aerosols, ice age cycles, and the distribution of continents and oceans. The research is conducted using a theoretical framework developed by the Principal Investigator (PI) in which stormtracks are characterized in terms of the flux of moist static energy (MSE) across them, where MSE is a measure of energy which includes the thermal energy associated with air temperature, the latent energy of water vapor released as heat during condensation, and the potential energy of air parcels lifted against the force of gravity. The MSE flux in stormtracks works in concert with MSE flux in circulations around large stationary pressure centers such as the Aleutian Low and the Bermuda High (referred to as stationary waves), and the circumglobal meridional overturning circulations (the Hadley and Ferrel cells), to transport energy from the tropics to the poles and balance the atmospheric energy budget. Much of the previous research on stormtracks has been conducted through analysis of the momentum budget and related quantities (potential vorticity and Eliassen-Palm flux, for instance), thus the MSE analysis of the present work offers a novel and complementary perspective.Preliminary work by the PI and colleagues shows compensation between MSE flux in stormtracks and stationary waves as a prominent feature of the seasonal cycle and the midlatitude response to El Nino events, while compensation between MSE flux in stormtracks and meridional overturning circulations appears in simulations of the atmopsheric response to greenhouse gases and the radiative effects of aerosols. The present work extends these investigations and seeks to determine the fundamental dynamics through which these compensations, in which changes in stormtrack MSE flux are accompanied by opposing changes in other forms of MSE flux, come about. The work is conducted through a combination of observational analysis and simulations with numerical models at varying levels of complexity.The work has societal relevance as well as scientific interest due to the importance of stormtrack behavior for human activities in the midlatitudes, including the continental US. In addition, one goal of the research is the identification of "emergent constraints" which can be used to assess the credibility of climate change simulations. Emergent constraints are relationships that emerge between model-to-model variations in simulated present-day climate (the predictor) and model-to-model differences in simulated future climate change (the predictand). Such constraints are used to assess the credibility of climate change projections, as models which incorrectly represent the predictor, which can be compared to real-world observations, are likely to produce comparable misrepresentations in their simulations of future climate change. Such tests of climate change projections are valuable given the use of climate models to inform climate change adaptation efforts. The project also supports a graduate student and the participation of an undergraduate, thereby providing for the education and training of the future workforce in this research area.

额叶天气系统通过后的温暖日子和寒冷的日子是美国大陆和其他中纬度地区冬季天气的熟悉特征。 这种交替不仅对当地天气，而且对于全球热量和水分的运输至关重要，因为温暖的潮湿空气跨越了从热带地区到杆的中间纬度，而较冷，更干燥的方向则相反。 这种南北的热量和水分交换在地球气候中起着至关重要的作用，防止杆子变得太冷，同时限制了热带地区的温度过高。 通过查看中纬度防突击塔（定义为最大天气系统活动区域），通常研究天气系统的这种气候影响。 在北半球，单独的暴风道集中在北太平洋北部和北大西洋，而在南半球，连续的暴风道延伸到不间断的南大洋上的“咆哮40年代”围绕“咆哮的40年代”。该项目旨在了解沿风暴的平均范围，以及在整体上循环的潮流，以及范围内的平均范围，以及对整体的循环范围，旋转的整体循环，构成了整体的趋势，构成了变化的变化。浓度，平流层气溶胶，冰河时代周期以及大陆和海洋的分布。 The research is conducted using a theoretical framework developed by the Principal Investigator (PI) in which stormtracks are characterized in terms of the flux of moist static energy (MSE) across them, where MSE is a measure of energy which includes the thermal energy associated with air temperature, the latent energy of water vapor released as heat during condensation, and the potential energy of air parcels lifted against the force of gravity. Stormtrack中的MSE通量与MSE通量合作，在大型固定压力中心（例如Alethian Low和Bermuda High（称为固定波））以及周围的环球倒闭循环（Hadley和Ferrel细胞），以从热带和平衡的Poles Enteral The Alterecle and Pollopics Complace Complate Complation Complucation和Bermuda High（称为固定的波浪），并与MSE Flux合作。 先前关于防暴的大部分研究都是通过分析动量预算和相关数量的分析（例如潜在的涡度和Eliassen-Palm通量），因此，对本工作的MSE分析提供了新颖而补充的观点。PI和同事在MESE中的响应范围和电气线中的MESE范围既有良好的范围又显示出良好的潮汐范围，这是一个有益的范围。 NINO事件，尽管突击队中的MSE通量与子午倾覆循环之间的赔偿是在模拟对温室气体的大气响应和气溶胶辐射作用的模拟中出现的。 目前的工作扩展了这些调查，并旨在确定这些补偿的基本动力，在这些动态中，突击队MSE通量变化伴随着其他形式的MSE Flux的变化。 这项工作是通过观察性分析和模拟与数值模型在不同级别的复杂性水平的组合结合进行的。由于暴风雨行为对中等程度的人类活动的重要性，包括美国大陆的美国活动，这项工作具有社会相关性和科学兴趣。 此外，该研究的一个目标是识别“紧急约束”，可用于评估气候变化模拟的信誉。紧急限制是模拟当前气候（预测指标）和模型对模型的模型变化之间出现的关系，在模拟未来的气候变化（预测和模拟）中存在差异。这些约束用于评估气候变化预测的可信度，因为可以将预测变量错误地代表预测因子（可以与现实世界观察值进行比较）可能会在对未来气候变化的模拟中产生可比的虚假陈述。 考虑到气候模型来为气候变化适应工作提供信息，这种气候变化预测的这种测试是有价值的。该项目还支持研究生和本科生的参与，从而为该研究领域的未来劳动力提供教育和培训。

项目成果

Atmospheric Diffusivity: A New Energetic Framework for Understanding the Midlatitude Circulation Response to Climate Change

大气扩散率：了解中纬度环流对气候变化响应的新能量框架

• DOI: 10.1029/2019jd031206
• 发表时间: 2020
• 期刊: Journal of Geophysical Research: Atmospheres
• 作者: Mooring, Todd A.;Shaw, Tiffany A.
• 通讯作者: Shaw, Tiffany A.

Surface Fluxes Modulate the Seasonality of Zonal-Mean Storm Tracks

• DOI: 10.1175/jas-d-19-0139.1
• 发表时间: 2020-02-01
• 期刊: JOURNAL OF THE ATMOSPHERIC SCIENCES
• 影响因子: 3.1
• 作者: Barpanda, Pragallva;Shaw, Tiffany A.
• 通讯作者: Shaw, Tiffany A.

Hydrological Cycle Changes Explain Weak Snowball Earth Storm Track Despite Increased Surface Baroclinicity

尽管表面斜压增加，水文循环变化解释了雪球地球风暴路径的弱化

• DOI: 10.1029/2020gl089866
• 发表时间: 2020
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Shaw, Tiffany A.;Graham, R. J.
• 通讯作者: Graham, R. J.

The Midlatitude Response to Polar Sea Ice Loss: Idealized Slab-Ocean Aquaplanet Experiments with Thermodynamic Sea Ice

中纬度地区对极地海冰损失的响应：热力学海冰的理想化板状海洋水行星实验

• DOI: 10.1175/jcli-d-21-0508.1
• 发表时间: 2022
• 期刊: Journal of Climate
• 影响因子: 4.9
• 作者: Shaw, Tiffany A.;Smith, Zoë
• 通讯作者: Smith, Zoë

Quantifying the Impact of Wind and Surface Humidity‐Induced Surface Heat Exchange on the Circulation Shift in Response to Increased CO 2

量化风和表面湿度的影响 — 诱导表面热交换对响应 CO 2 增加的循环变化的影响

• DOI: 10.1029/2020gl088053
• 发表时间: 2020
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Tan, Zhihong;Shaw, Tiffany A.
• 通讯作者: Shaw, Tiffany A.